/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.runners.gaia.translation.wrappers.streaming.stableinput;



import com.bff.gaia.api.common.state.ListState;



import java.util.stream.Stream;

import java.util.stream.StreamSupport;



import static com.bff.gaia.unified.vendor.guava.com.google.common.base.Preconditions.checkNotNull;



/** A non-keyed implementation of a {@link BufferingElementsHandler}. */

public class NonKeyedBufferingElementsHandler<T> implements BufferingElementsHandler {



  static <T> NonKeyedBufferingElementsHandler<T> create(ListState<BufferedElement> elementState) {

    return new NonKeyedBufferingElementsHandler<>(elementState);

  }



  private final ListState<BufferedElement> elementState;



  private NonKeyedBufferingElementsHandler(ListState<BufferedElement> elementState) {

    this.elementState = checkNotNull(elementState);

  }



  @Override

  public Stream<BufferedElement> getElements() {

    try {

      return StreamSupport.stream(elementState.get().spliterator(), false);

    } catch (Exception e) {

      throw new RuntimeException("Failed to retrieve buffered element from state backend.", e);

    }

  }



  @Override

  public void buffer(BufferedElement element) {

    try {

      elementState.add(element);

    } catch (Exception e) {

      throw new RuntimeException("Failed to buffer element in state backend.", e);

    }

  }



  @Override

  public void clear() {

    elementState.clear();

  }

}